[WH4K]

I can think of a few good reasons that sub skippers would historically have stayed out of enemy harbors, which aren't reflected in the game:


1) currents. Many real-world harbors have tides or local currents that would make sneaking in submerged risky or impossible, unless one wanted to storm in at flank speed & quickly exhaust one's battery.


2) channels, shoals, etc. IOW, real-world navigation conditions that made harbor pilots (and lighthouses and channel marker buoys) necessary. You couldn't necessarily safely approach from just any direction without running into something, especially submerged, even at known deepwater ports. Especially so at not-so-deepwater ports.


Then we have the submarine nets and mines.

It's called Silent Hunter 4, not Littoral Navigation Simulator 4, so it's in deep water, away from land, that conditions are most realistic.